Collateralized Transactions (Details) - USD ($) $ in Thousands |
Mar. 31, 2016 |
Dec. 31, 2015 |
|---|---|---|
| Financial instruments owned and pledged | ||
| Financial instruments owned and pledged, where counterparty has right to repledge | $ 247,652 | $ 259,175 |
| Securities received as collateral: | ||
| Securities borrowed | 639,071 | 437,220 |
| Securities purchased under agreements to resell | 14,985 | |
| Total amounts related to collateralized transactions | 639,071 | 452,205 |
| Equity securities | ||
| Financial instruments owned and pledged | ||
| Financial instruments owned and pledged, where counterparty has right to repledge | 244,868 | 232,731 |
| Exchange traded notes | ||
| Financial instruments owned and pledged | ||
| Financial instruments owned and pledged, where counterparty has right to repledge | $ 2,784 | $ 26,444 |